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MTS70-0512ACW going into protection

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    MTS70-0512ACW going into protection

    Hi,

    I've spend the last 3 days trying to figure out what is causing this smps to go into protection.
    Because it only powers on for a split second it's almost impossible to measure anything.
    That's why I removed the oscillator board (it's a separate board) and powered it externally.
    The TEA1610T showed me this at the gate outputs:

    So I assumed a faulty driver and was a bit surprised it went into protection instead of blowing up the FET's.
    I replaced the IC (even twice) and I still get the same problem.
    Does anyone have an idea what is going on here?

    Thanks,

    Jenne

    #2
    Re: MTS70-0512ACW going into protection

    Are you sure that you do not have a short circuit in the secondary side of the switching power supply or even in the primary side of the switching power supply

    Have you checked the startup capacitor with a ESR capacitor tester

    ( do not use a UF capacitor tester this testing would not tell you what you need to know)

    to see this if might be the issue

    I would even recommend that you compare the results with a new capacitor of the same UF value for comparison of values and if they are more than 10% difference

    I would recommend just replacing them

    In fact I would check every capacitor that is less than 100uf

    Please show a clear and focus pictures of front and back of the board in question
    Last edited by sam_sam_sam; 03-11-2021, 07:00 PM.
    9 PC LCD Monitor
    6 LCD Flat Screen TV
    30 Desk Top Switching Power Supply
    10 Battery Charger Switching Power Supply for Power Tool
    6 18v Lithium Battery Power Boards for Tool Battery Packs
    1 XBox 360 Switching Power Supply and M Board
    25 Servo Drives 220/460 3 Phase
    6 De-soldering Station Switching Power Supply 1 Power Supply
    1 Dell Mother Board
    15 Computer Power Supply
    1 HP Printer Supply & Control Board * lighting finished it *


    These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

    1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
    2 Hem Saw Computer Stack Board

    All of these had CAPs POOF
    All of the mosfet that are taken out by bad caps

    Comment


      #3
      Re: MTS70-0512ACW going into protection

      Sounds like the PSU starts up, sees a short on the output, or something wrong with the feedback, then shuts down. Post some high resolution straight shot pictures top and bottom.
      Last edited by CapLeaker; 03-12-2021, 06:16 AM.

      Comment


        #4
        Re: MTS70-0512ACW going into protection

        All the caps have been tested and even replaced without reason and it didn't make a difference. I took some pictures of the board, but keep in mind that the small boards are out of place zo I could reach them to measure while the PSU is running. I took a separate picture of the oscillator board that I'm now running from a bench supply which gives me the result from my initial post.
        Maybe one more thing, when I power the TEA1610T without it being on a pcb or without any passives it off course doesn't oscillate because of the missing components but it isn't working as described in the startup phase from the datasheet. Check p.5 fig 5
        https://cdn.badcaps-static.com/pdfs/...9af820868e.pdf
        Here you can clearly see that the low gate will rise according to the Vdd but the high gate stays low. This is what I get: (blue is low gate, yellow is high gate)

        So what am I missing here? Maybe some external input that will pull the high gate output low?






        Thank you for your help already

        Comment


          #5
          Re: MTS70-0512ACW going into protection

          Is It the pictures but the one of the bottom of the board looks like some soldering joint looking very bad like they did not get soldered correctly it looks like some pins have what looks like flux between the pins and the solder

          I would recommend reflowing the solder or remove the solder completely and reapply the solder
          Last edited by sam_sam_sam; 03-12-2021, 04:17 PM.
          9 PC LCD Monitor
          6 LCD Flat Screen TV
          30 Desk Top Switching Power Supply
          10 Battery Charger Switching Power Supply for Power Tool
          6 18v Lithium Battery Power Boards for Tool Battery Packs
          1 XBox 360 Switching Power Supply and M Board
          25 Servo Drives 220/460 3 Phase
          6 De-soldering Station Switching Power Supply 1 Power Supply
          1 Dell Mother Board
          15 Computer Power Supply
          1 HP Printer Supply & Control Board * lighting finished it *


          These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

          1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
          2 Hem Saw Computer Stack Board

          All of these had CAPs POOF
          All of the mosfet that are taken out by bad caps

          Comment


            #6
            Re: MTS70-0512ACW going into protection

            No, that's just flux residue you're seeing. I did work on the board allot and didn't clean it between each thing i tried.

            Comment

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